Other family members in the series of four pictures, which were released by Kensington Palace, are grandparents Prince Charles and Camilla, Carole Middleton, Michael Middleton, Pippa Matthews, James Matthews and James Middleton.
Royals arrive at St James' Palace for Prince Louis' christening
In one photo, Kate and William are joined by their children, along with the Duke and Duchess of Sussex, the Prince of Wales and the Duchess of Cornwall, and the Middleton family including Kate's sister Pippa Matthews and her husband James.
Members of the Royal Family appear in another photo without the Middletons and a third photo features the Cambridge five and the fourth photo is an image of just Kate and Louis.
The photographs were taken in the morning room and garden at Clarence House.
Prince Louis was then christened in a private, 40-minute ceremony conducted by the Archbishop of Canterbury Justin Welby in the Chapel Royal last Monday.
It had been reproduced by dressmaker to the Queen Angela Kelly and was worn by his older siblings, George and Charlotte at their christenings.
Little Louis, who is fifth in line to the throne, is to have six godparents.
The Duke and Duchess of Cambridge chose two hymns, two lessons and two anthems for the christening of their son. The Hymns were O Jesus, I Have Promised and Lord of All Hopefulness.
The lessons were from Mark 10: 13-16, read by godparents Lucy Middleton and Ephesians 3: 14-19, read by Guy Pelly.
William tells Kate 'There's Arthur!' as couple spot Sun's royal photographer whilst showing off new baby boy Prince to the world
The anthems were This is the day which the Lord hath made, which was composed for the Cambridges' Wedding in 2011, and Suo Gân, a traditional Welsh lullaby.
Both were performed by The Choir of Her Majesty's Chapel Royal.
The photographer who took the snap, Matt Holyoak said: "I was truly honoured at being asked to take the official photographs at the christening of Prince Louis, and to witness at first hand such a happy event.
“Everyone was so relaxed and in such good spirits, it was an absolute pleasure. I only hope I have captured some of that joy in my photographs."
Princess Charlotte cheekily reminds the press that they're not invited to her brother Prince Louis' christening party
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